Thread-cutting device for sewing-machines



No. 749,012. PATENTED JAN. 5, 1904.

E. B. ALLEN.

THREAD CUTTING DEVICE FOR SEWING MACHINES. APPLIoATIon FILED MAR. 17, 1903.

no MODEL.

UNITED STATES Patented January 5, 1904. v

PATENT OFFICE.

EDWARD B. ALLEN, OF ELIZABETH, NEW JERSEY, ASSIGNOR TO THE SINGER MANUFACTURING COMPANY, A CORPORATION OF JERSEY.

THREAD-CUTTING DEVICE FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 749,012, dated January 5, 1904.

Application filed March 17, 1903.

To all whom it may concern:

Be it known that I, EDWARD B. ALLEN, a citizen of the United States, residing at Elizabeth, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Thread-Cutting Devices for Sewing-Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention has for its object to provide a thread-cutting and thread-holding device for sewing machines by which the lower thread will be severed beneath the work at the end of a sewing operation by the act of removing the work from a Work-clamp or from beneath the presser-foot of the machine and which thread-cutting and thread-holding device will hold the end of the thread until after the commencement of the next stitching operation.

To this end the improved thread cutting and holding device comprises a normally stationary knife mounted on the throat-plate or work-plate of the machine adjacent to the needle-hole thereof and in such position that as the work is drawn out by the attendant in the act of removing the same from beneath the upper jaw of the work-clamp or from beneath the presser-foot of the machine the thread will be brought against the cutting edge of the thread-severing blade or cutter and also preferably between two nipping surfaces formed on thread-holding arms or parts yieldingly pressed together at'the time when the thread is to be severed, but the pressure on which will be relieved after the com mencement of the next stitching operation to renipping arms or members. Fig. 4 is a detail Serial No. 148,202. (No model.)

view'of the throat-plate with both the cutting-blade and the thread-nipping arms removed, and Fig. 5 is a detail view of the thread-cutting blade. Fig. 6 is a central vertical longitudinal section through the throatplate and the attached thread cutting and holding device and also through the upper jaw of the clamp.

Referring to the drawings, 12 denotes a work-plate, which in the present instance is intended to be movably mounted on the bedplate of a buttonhole-stitching machine and which plate 12 supports a plate 13, which is the lower member of a buttonhole clamp mounted to slide in ways transversely to the plate 12. Secured to the plate 13 is a throatplate 14, havingin the present instance a longitudinal slit or opening 15 for the reception of a buttonhole-cutter and having a transverse needle hole or throat 16 at one end of said cutter-slit15.

Attached to the throat-plate 14: is a small blade or cutter l7, beveled to form a sharp cutting edge at the end thereof which is adjacent to the needle-hole 16. The blade or cutter 17 is held in place by a dowel-pin'18 and a screw 19, said screw serving as a pivot for two small thread-nipping arms 20, located beneath the cutting-blade 17. The threadnipping arms 20 are cut away at their free ends to form a V-shaped recess which registers with a slot 24, communicating with that side of the needle-hole which is adjacent to the ends of said arms. The thread-nipping arms 20 are preferably mounted on the throat-plate 14 and are also preferably provided on their outer sides with small lugs 21 to be engaged'by the ends of spring-fingers 22 when the parts are in the position shown in Fig. 1,so as to yieldingly press the said thread-nipping arms toward each other. The spring-fingers 22 are rigidly attached to the sliding plate 13 by screws 23, but their thin middle portions are sufticiently elastic to permit the free ends of said fingers to have a limited movement, so as to yieldingly press the thread-nipping arms 20 toward each other when the spring-fingers are in engagement with the lugs 21 on said arms; but when the sliding plate 13 is moved to the position shown in Fig. 2 the said fingers will be released from said lugs and the pressure on the end of the thread which has been held by the thread-nippin g fingers will be released.

The operation of the device is as follows: At the end of a stitching operation, as when the stitching of a buttonhole has been completed, and when the work has been released by slightly lifting the upper jaw 25 of the clamp the attendant draws out the work from beneath the said upper jaw of the clamp in the direction indicated by the arrow in Fig. 1, and in so doing draws the lower thread into the slit 24, communicating with the needle-hole in the throat-plate and into the V- shaped recess between the ends of the threadnipping arms 20 and between said arms until it is brought against the sharpened end of the thread-cutting blade which crosses the line of the said slot and recess. This operation of drawing thread against the edge of the cutting-blade forces the thread between the thread-nipping arms in such a manner that when the thread is severed the end of the thread, which of course is the lower thread of a two-thread machine, is retained by said thread-nipping arms so long as the springfingers 22 press against the lugs 21 on said arms. When the stitching of the next buttonhole is commenced, the plate 13, which is the lower plate of the work-clamp, moves in the direction denoted by the arrowin Fig. 2, carrying the fingers 22 away from the lugs 21 on the nipping-arms 20, and thereby relieving the nipping pressure on the thread in such a manner as to release the thread from the thread-holding device.

Although the form of the invention as herein illustrated is specially intended for use in severing the lower thread of a twothread buttonhole-stitching machine, the invention is not to be understood as being limited to such use, as the invention may be adapted for use on other styles of sewingmachines to sever the lower thread beneath the work at the completion of a stitching operation, it being only necessary to this end that the thread cutting and nipping device should be so disposed beneath the presserfoot or upper work-holding member of a sewing-machine as to cause the lower thread to be drawn against the stationary cuttingblade as the work is removed from the machine. Also the invention is not to .be understood as being limited to the details of construction herein shown and described, as such details may be varied widely without departing from the spirit of the invention.

It will be seen from the sectional view Fig. 6 that the cutting edge of the blade or knife 17 is approximately on a level or flush with the top of the throat-plate 14, so that the thread may be severed close to the lower side of the work as the latter is drawn by the attendant in the direction denoted by the arrow in Fig. 2 to bring the said thread against the said cutting edge of the said blade. The said blade or cutter is preferably made quite thin, so that its upper surface is also approximately on a level with the surface of the throat-plate, and the said blade or cutter therefore offers no obstruction to the proper clam ping and holding of the work.

Having thus described my invention, I claim and desire to secure by Letters Patent 1. A thread cutting and holding device for sewing-machines, adapted to sever and hold the lower thread beneath the work, comprising the combination with a throat-plate, of a stationary thread-cutting blade having its cutting edge arranged adjacent to the needlehole of the said throat-plate and approximately flush with the top of the latter, said throat-plate having a slot or opening extending from said needle-hole to the cutting edge of said blade, to form a thread-passage into which the thread may be drawn for the threadsevering operation, and a thread-nipping device independent of and arranged beneath said blade and consistingofyieldingly-mounted parts cut away to form a recess registering with the said thread passage in the throat-plate.

2. A thread cutting and holding device for sewing-machines, adapted to sever the lower thread beneath the work, comprising the co mbination with a throat-plate, of a stationary thread-cutting blade having its cutting edge arranged adjacent to the needle-hole of said throat-plate, the latter having a threadpassage extending from said needle-hole to the cutting edge of said blade, a thread-nipping device independent of and arranged beneath said blade, and consisting of two parts recessed to form a portion of said thread passage, and means for yieldingly pressing the said parts toward each other for the thread nipping or holding operation.

3. A thread cutting and holding device for sewing-machines, consisting of the combination with a throat-plate having a needle-hole provided with a slot or opening at one side, of a fixed cutting-blade having its cutting edge arranged adjacent to said needle-hole and crossing said slot, pivotallymounted thread-nipping arms arranged beneath said cutting-blade and cut away to form a recess registering with the slot extending from the needle-hole, and means for yieldingly pressing said arms toward each other for the thread-nipping or thread-holding operation.

4. A thread cutting and holding device for sewing-machines consisting of the combination with a throat-plate provided with a needle-hole having a slot or opening at one side, of a fixed cutting-blade having its cutting edge arranged adjacent to said needle-hole and crossing said slot, pivotally-mounted IIO thread-nipping arms arranged beneath said cutting-blade and cut away to form a recess registering with the slot extending from the needle hole, spring fingers for yieldingly pressing the said arms toward each other for the thread-nipping 0r thread-holding operation, and a movable part by which the said spring-fingers are carried so that said fingers may be disengaged from the said thread-nipping arms, to release the thread. 10

In testimony whereof I affix my signature in presence of two witnesses.

EDWARD B. ALLEN. Witnesses:

ALEX. BOYD, HENRY J. MILLER. 

